Controlled ovarian hyperstimulation alters mice placental function / 解放军医学杂志

ABSTRACT

Objective To observe and assess the effect of controlled ovarian hyperstimulation (COH) on fetal weight and placental function of mouse model. Methods In vitro fertilized (IVF) blastocysts were transferred to non-stimulated pseudopregnant mice (NSP group, n=6) and superovulated pseudopregnantt mice (SOP group, n=6). At 18.5 d of embryonic age (E18.5 d), the fetal weight and placental weight were examined. The areas of labyrinth layer and junction layer of placenta were measured using microscopic image software. The apoptosis in the placenta was detected by TUNEL. The levels of glutathion (GSH) and malonaldehyde (MDA) in placenta were detected separately by spectrophotometry and barbiturate method. The expression levels of amino acid transporter Snat1, Snat2, Snat4, Lat1, Lat2, Cd98, and Taut mRNA in placenta were detected by qRT-PCR. The SNAT2 protein levels in microvillous membrane (MVM) of placenta were detected by Western blotting. Results At E18.5d, compared with the mice in SOP group to those in NSP group, the mean weights of fetal and placenta were significantly lower [(1.37±0.13) g vs. (1.75±0.13) g; (0.14±0.02) g vs. (0.17±0.01) g, P<0.001)]. The apoptosis rates increased in both labyrinth layer and junction layer of placenta [(7.57±1.23) % vs. (4.62±0.91) %, P<0.001; (5.28±0.99) % vs. (3.27±0.69) %, P=0.002]. The GSH level in placenta decreased obviously [(5.21±1.55) μmol/g prot vs. (8.45±1.60) μmol/g prot, P=0.005], while the concentration of MDA increased markedly [(1.35±0.52) nmol/g prot vs. (0.56±0.19) nmol/g prot, P=0.005]. The levels of Snat1, Snat2, Lat2 and Tau mRNA in the placenta were down regulated (0.77±0.13, 0.65±0.18, 0.69±0.18, 0.73±0.07, P<0.001), and the SANT2 protein levels in placental MVM were decreased significantly [(0.32±0.01) vs. (0.65±0.15), P<0.001]. Conclusion Controlled ovarian hyperstimulation may alter placental function, and induced placental oxidative stress might be a critical factor of abnormal placental function.